Turning slide for open hole operation

ABSTRACT

A turning slide is positioned on the body of a sidewall sampling apparatus to allow the sidewall sampling apparatus to be properly positioned in a borehole for the taking of a sample. The sidewall sampler with turning slide may be effectively used in deviated boreholes.

United States Patent 1 Wolk Dec. 4, 1973 [54] TURNING SLI DE FOR OPENHOLE 3,268,016 8/1966 Bell l75/4.5l OPERATION 3,338,317 8/1967 Shorel75/4.5l

[75] Inventor: Piero Wolk, Houston, Tex.

[73] Assignee: Dresseljlndustries, Inc., Dallas, Tex.

[22] Filed: Oct. 17, 1972 [21] App]. No.: 298,225

[52] US. Cl. 175/4, l75/4.5l

[51] Int. Cl E2lb 49/04 [58] Field of Search 175/2, 4, 4.51, 58, 175/323[5 6] References Cited UNITED STATES PATENTS 3,003,569 10/1961 Porteretal 175/4 Primary Examiner-David H. Brown Attorney-Robert W. Mayer eta].

[57] ABSTRACT A turning slide is positioned on the body of a sidewallsampling apparatus to allow the sidewall sampling apparatus to beproperly positioned in a borehole for the taking of a sample. Thesidewall sampler with turning slide may be effectively used in dfeviatedboreholes.

6 Claims, 7 Drawing Figures PATENTEDBEB 4191s 3.776321 SHEET 10? 2CONTROL EQUIPMENT FIG.I

PRIOR ART FIG. 2

PRIOR ART PATENTEDDEC 4m: v 3.776.321

I SHEET ESP 2 TURNING SLIDE FOR OPEN HOLE OPERATION BACKGROUND OF THEINVENTION The present invention relates to a system for obtainingsamples of subsurface formations traversed by a borehole and moreparticularly to an apparatus for insuring that a sidewall samplingdevice will be properly oriented in the borehole for the taking of .asample.

The exploration and production of oil and gas and other naturalsubstances found in formations or strata of earth or rock below thesurface of the earth is generally achieved by means of a boreholedrilled into the formations. Although various techniques are availablefor gaining information with respect to the location and character offormations underlying previously undrilled areas of the surface, suchinformation is only approximate. Thus, other techniques are oftenutilized during and after drilling operations to obtain samples of thematerial being penetrated. One well known technique for obtaining thesesamples includes cutting a core of the rock or earth by means of atubular-shaped drill bit affixed at the outer end of a drill string.This method is time consuming and expensive since each time a core is tobe taken and raised to the surface the entire drill string must first beremoved from the borehole. Thus, cores are generally taken only atlimited intervals throughout the drilling operations. Retractable corebarrels that can be returned to the surface through the drill string arealso known; however, such core barrels require a substantial amount ofspecialized equipment including special elements in the drill string.

A sampling technique that may be performed at sub stantially less costinvolves the use of wireline tool for selectively obtaining samples fromthe wall of the borehole at any desired level. This tool, commonly knownas a sidewall sampler, includes an elongated body containing a pluralityof apertures along its length which function in the manner of short gunbarrels with each such barrel having an explosive charge and a samplecontainer projectile adapted to be laterally discharged thereby into thewall of the borehole. Electrical circuitry for achieving ignition of thecharges from a control point at the surface is generally included.Further, since the cores taken by the sample container projectiles areintended to be recovered, the projectiles are generally coupled to thesidewall sampler body by means of one or more small cables. Thus, whenthe sidewall sampler body is withdrawn from the borehole these cablespermit the sample container projectiles containing the cores to bepulled out of the borehole wall and carried to the surface along withthe sidewall sampler body.

In operation the sidewall sampler may be lowered by means ofconventional cabling and hoist equipment to that section of the boreholeadjacent the formations sought to be sampled. Thereafter, one or more ofthe guns may be fired to discharge corresponding sample containerprojectiles laterally into the adjacent formations. When the sampler isdrawn up the borehole, the aforementioned small cables which remainattached to both the sidewall sampler body and the embedded samplecontainer projectiles serve to drag the projectiles out of the formationas the sampler is drawn up the borehole.

Notwithstanding the advantages of selectivity and speed of samplingafforded by the sidewall sampler, certain problems have been encounteredwith use of the sidewall sampler in inclined boreholes. Boreholes thatdeviate from a vertical position generally have an oblong cross sectionwith the largest axis of the borehole oriented in the relative verticaldirection. During the sampling operation, the sidewall sampler bodyrests against the bottom of the deviated borehole and should thesampling guns be facing the top of the borehole, the sample containerprojectiles must cross the borehole before reaching the formation to besampled. This may result in the snapping of the cables connecting thesam ple container projectiles to the sidewall sampler body and loss ofthe desired sample. Unfortunately, many of the sidewall samplers areconstructed in such a manner that the center of gravity of theinstrument is located at a position that results in the sidewallsampling apparatus being oriented in the boreholes in the undesirableposition of having the sampling guns facing toward the top of theborehole. Prior art methods of combating this problem have beenconcerned with centralizing the sidewall sampling apparatus in order toinsure that the apparatus will be properly in the borehole. The presentinvention attacks the problem in a substantially different manner byproviding means for turning the sidewall sampling apparatus over so thatthe sampling guns are facing in a relatively downward direction.

DESCRIPTION OF THE PRIOR ART In US. Pat. No. 3,272,268 to A. J. Tn'conet al. patented Sept. IS, 1966, a sidewall sampling apparatus is shown.This sidewall sampling apparatus includes an elongated shaft containinga plurality of apertures which function in the manner of short gunbarrels. An explosive charge is positioned in each of such gun barrelsand a projectile adapted to be laterally discharged thereby into thewall of the borehole is also positioned in the gun barrel. When theexplosive charges are detonated, the projectiles are fired into theformations adjacent the apparatus. The projectiles are connected to theapparatus by cables. When the sampler is drawn up the borehole, theaforementioned cables which remain attached to both the sampler and theembedded projectile serve to drag the projectile out of the formationthereby carrying the desired sample to the surface.

SUMMARY OF THE INVENTION The present invention provides a sidewallsampling apparatus that may be used effectively in deviated boreholes.The sidewall sampling apparatus includes a body portion adapted to bemoved through a borehole by a cable. At least one sampling projectile ispositioned in the body of the sampling apparatus. Means are provided forfiring the sampling projectile into the formations surrounding theborehole and means for connecting the sampling projectile to the body ofthe apparatus are included. The sidewall sampling apparatus includesmeans for turning the apparatus once it has been positioned proximatethe formations to be sampled.

The above and other features and advantages of the present inventionwill become apparent from consideration of the following detaileddescription of the invention when taken in conjunction with theaccompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a pictorial view partly incross section of a prior art sidewall sampler positioned in a borehole.

FIG. 2 is a view of one of the coring projectiles of the sampler shownin FIG. 1 after the projectile has been fired into the formationssurrounding the borehole.

FIG. 3 is an end view of a sidewall sampling apparatus of the presentinvention positioned in a borehole.

FIG. 4 is an end view of a sidewall sampling apparatus of the presentinvention after it has been moved to a position for firing.

FIG. 5 is a side view of a section of the sidewall sampling apparatusshown in FIGS. 3 and 4.

FIG. 6 is an end view of another embodiment of the present invention.

FIG. 7 is an end view of the apparatus shown in FIG. 6 in a boreholeafter it has been moved to a position for firing.

DETAILED DESCRIPTION OF THE INVENTION Referring now to FIG. 1, asidewall sampling apparatus 1 of the prior art is shown. FIG. 1 shows atypical borehole 2 drilled into the earth 3 containing the prior artsidewall sampler l suspended therein by a cable 4 which is secured tothe sidewall sampler 1 by means of a cable head 5. The cable 4 may be ofconventional design to include one or more electrical conductors asdesired. The cable 4 is connected to control equipment 6 located at thesurface and is used to move the sidewall sampler 1 in and out of theborehole 2. The depth at which the sidewall sampler 1 is positioned inthe bore hole 2 may be determined by means of a conventional measuringwheel 7 from which the cable 4 is suspended and over which the cable 4is drawn.

As shown, the sidewall sampler 1 includes an elongated body 8 having aplurality of projectiles 9 arranged in a manner to be dischargedlaterally into the wall of the borehole 2 as will hereinafter beexplained in greater detail. As illustrated in FIGS. 1 and 2, eachprojectile 9 is also connected to the body 8 by means of one or morecables 10 or other type of flexible linking means of some suitabledesign.

Referring to FIG. 2, there is depicted therein a section of the borehole2 and body 8 hereinbefore mentioned wherein the projectile 9 has beendischarged into the wall of borehole 2 in a manner to take a sample ofthe adjacent earth 3. As shown in FIGS. 1 and 2 the projectile 9 isprovided with enlarged cutting edge 11 to cut a core hole 12 of adiameter larger than that of the body of the projectile 9 to prevent theprojectile 9 from becoming too tightly embedded in the more impactedformation of the earth 3. The attached cables 10 should be long enoughto permit the projectile to penetrate the earth 3 at depths sufficientto pass beyond any drilling mud which may be deposited on the face ofthe wall of the borehole 2. However, when the body 8 is drawn out of theborehole 2, the cables 10 will serve to pull each projectile 9 out ofits respective core hole 12 and to carry it upward in order that thecores contained in each projectile 9 may be recovered at the surface fortesting and analysis. It is thus apparent that since boreholes 2 such asthat depicted in FIGS. 1 and 2 are of a relatively small diameter, body8 must of necessity be even smaller in diameter and consequently the gunbarrel 13 of each gun must be at least somewhat shorter in length thanthe diameter of the body 8.

Referring now to FIG. 3, a sidewall sampler 14 of the present inventionis shown positioned in a deviated borehole 15. The borehole 15 has anelongated cross section generally found in deviated boreholes. When thesidewall sampler 14 is resting on the lower side 16 of the borehole 15,there is a considerable distance be tween the body 17 of the sampler l4and upper side 18 of the borehole 15. It will therefore be appreciatedthat the sampling projectile 19 of the sampler 14 will be re quired totravel a substantial distance before reaching the upper side 18 ofborehole l5 and that there is a considerable risk of breaking anylinking cable between the body 17 of the sampler l4 and the projectile19 when the projectile 19 is fired into the formations. The geometry andweight distribution of the sampler 14 is such that the sampler tends torest on the lower side 16 of deviated boreholes.

The sidewall sampler 14 of the present invention includes a turningslide 20 that allows the sampler 14 to be turned in the borehole 15 sothat the sampling pro jectile 19 is moved to a position facing the lowerside of the borehole 16 as shown in FIG. 4. The turning slide, as shown,is a vane or ridge that extends in spiral fashion along at least aportion of the length of the body 17 of the sidewall sampler 14. Theturning slide 20 contacts the lower side 16 of the borehole l5 andmovement of the sampler 14 along the borehole 15 turns the sampler tothe position shown in FIG. 4. With the sampler 14 in the position shownin FIG. 4, the sampling projectile 19 may be fired directly into theformations and the risk of breaking the cables that connect the samplingprojectile 19 to the body 17 of the sampler 14 is reduced or eliminated.A rigid stand-off 31 constructed of metal or other rigid materialcontacts the lower side 16 of the borehole 15 and maintains the sampler14 in proper position for firing.

A mercury switch 21 is positioned in the sampler 14 to provide anindication that the sampler is in position for firing. The mercuryswitch 21 may be of conventional design, for example, it could be thetype shown on page 282 of the Electronics and Nucleonics Dictionary,Cooke and Markus, McGraw-Hill, 1960. The mercury switch 21 closes anelectrical circuit that includes a signal means (not shown) at thesurface when the sampler 14 is in position for firing as shown in FIG.4. The mercury switch 21 remains open when the ssampler is in otherpositions such as that shown in FIG. 3.

Referring now to FIG. 5, a side view of a portion of the sampler body 17is shown. The turning slide 20 is mounted along at least a portion ofthe length of the body 17 of the sampler 14 at an angle 22 to thecentral axis of the sampler 14. The particular angle 22 shown in theembodiment of FIG. 5 is 15; however, it is to be understood that otherangles could be employed.

Referring now to FIGS. 6 and 7, another embodiment of the presentinvention is shown. The sidewall sampling apparatus 23 includes asampler body 24 and a sampling projectile 25 adapted to be fired intothe formations surrounding a borehole 26. A turning slide 27 ispositioned on the outside of body 24 for turning the sampler 23 to aposition suitable for firing. A mercury switch 28 is positioned in thesampler 23 to complete an electrical circuit to the surface and providea signal indicating that the sampler is in position for firing. A rigidstand-off 29 and a flexible rubber stand-off 30 contact the boreholewalls when the sampler 23 has been turned to a position for tiring andmaintain the sampler 23 in the proper position for firing.

The sidewall sampling apparatus is lowered into a borehole. If theborehole is deviated, the sampler will rest on the lower side of theborehole due to the forces of gravity. if the sampler is not in aposition for firing once the sampler reaches the proper depth forsampling, the mercury switch in the sampler will remain open and theoperator will know that additional procedures are necessary. The sampleris moved up the borehole a short distance. The turning slide contactsthe wall of the borehole and turns the sampler to a position for firing.Once the sampler is in position for firing, the mercury switch willclose and the operator will receive a signal indicating that the samplermay be fired.

The embodiments of an invention in which an exclusive property orprivilege is claimed are defined as follows:

1. An apparatus for sampling formations traversed by a borehole,comprising:

a sampler body;

sampling projectile means positioned in said body for receiving a sampleof the formations;

means for firing said sample projectile from said body section to theformations;

linkage means connecting said body section and said sampling projectile;and

means for turning said sampler body.

2. The apparatus of claim 1 wherein said means for turning said samplerbody is a spiral ridge extending along at least a portion of saidsampler body.

a 3. The apparatus of claim 2 including means for pro viding a signalonce said sampler body has been turned.

4. The apparatus of claim 3 wherein said means for providing a signalincludes a mercury switch.

5. The apparatus of claim 4 including a rigid stand-off elementextending from said sampler body proximate said sampling projectilemeans.

6. The apparatus of claim 5 including a flexible standoff elementextending from said sampler body.

I UNITED STATES PATENT OFFTCE CERTIFICATE CORRECTION Patent No. YjJZlDated December Lu 1973 Inventor(s) PF'LQI'O Wolk It is eert ifi'ed thaterror appears in the above-identified patent and that said LettersPatent are hereby corrected as shown below:

Column 6, "line 3 "linkage" should read --linl ing Signed and sealedthisQOth day ofA'pril 197A.

(SEAL) Attest:

EDWARD MELETCHER R. c. MARSHALL DAJN Attesting Officer Commissioner 0:5.Patents FORM PO-IOSQ (IO-59) USCOMM-DC 60876-P69 1: us. GOVIRNMENTrmu'rms OFFICE In, o-us-au.

1. An apparatus for sampling formations traversed by a borehole,comprising: a sampler body; sampling projectile means positioned in saidbody for receiving a sample of the formations; means for firing saidsample projectile from said body section to the formations; linkagemeans connecting said body section and said sampling projectile; andmeans for turning said sampler body.
 2. The apparatus of claim 1 whereinsaid means for turning said sampler body is a spiral ridge extendingalong at least a portion of said sampler body.
 3. The apparatus of claim2 including means for providing a signal once said sampler body has beenturned.
 4. The apparatus of claim 3 wherein said means for providing asignal includes a merCury switch.
 5. The apparatus of claim 4 includinga rigid stand-off element extending from said sampler body proximatesaid sampling projectile means.
 6. The apparatus of claim 5 including aflexible stand-off element extending from said sampler body.